Usage

Add hidden default data

Please use TableField->setExtraData() to specify additional (non-editable) data. You might use the following code
that shows the Player of Team with a particular Team ID and automatically saves new Players into this Team.

In this example, you'll note that we're setting TeamID to $this->ID. This works well if you're including a TableField
as an editable field on a getCMSFields() call.

Required Fields

Due to the nested nature of this fields dataset, you can't set any required columns as usual with the
RequiredFields** on the TableField-instance for this.
Note: You still have to attach some form of Validator to the form to trigger any validation on this field.

Nested Table Fields

When you have TableField inside a ComplexTableField, the parent ID may not be known in your
getCMSFields() method. In these cases, you can set a value to '$RecordID' in your TableField extra data, and this
will be populated with the newly created record id upon save.

Known Issues

A TableField doesn't reload any submitted form-data if the saving is interrupted by a failed validation. After
refreshing the form with the validation-errors, the TableField will be blank again.

You can't add visible default data to columns in a TableField, please use setExtraData